jsonrpc: uds support for Windows

I could not find a way to get mio 0.7 running with Windows' uds. So,
until tokio-rs/mio#880 (deprecrated/mio-uds#7)
is implemented in Mio we use a simple blocking event loop for Windows.

That's fine, it's just for the RPC. We could potentially see some load
on a server, but it'd be on UNIX so Everything Is Fine ™️.

Signed-off-by: Antoine Poinsot <[email protected]>

Cargo.toml

@@ -36,4 +36,7 @@ rusqlite = { version = "0.24.1", features = ["bundled"] }
 # For the JSONRPC API
 jsonrpc-core = "15.1.0"
 jsonrpc-derive = "15.1.0"
+[target.'cfg(not(windows))'.dependencies]
 mio = { version = "0.7.5", features = ["default", "os-poll", "os-util", "uds"] }
+[target.'cfg(windows)'.dependencies]
+uds_windows = "0.1.5"

src/jsonrpc/mod.rs

@@ -8,10 +8,12 @@ use std::{
     time::Duration,
 };
 
-use mio::{
-    net::{UnixListener, UnixStream},
-    Events, Interest, Poll, Token,
-};
+use mio::{Events, Interest, Poll, Token};
+
+#[cfg(not(windows))]
+use mio::net::{UnixListener, UnixStream};
+#[cfg(windows)]
+use uds_windows::{UnixListener, UnixStream};
 
 const JSONRPC_SERVER: Token = Token(0);
 
@@ -23,17 +25,6 @@ impl RpcApi for RpcImpl {
     }
 }
 
-/// Set up the poller used to listen on the Unix Domain Socket for JSONRPC messages
-pub fn jsonrpcapi_setup(socket_path: PathBuf) -> Result<(Poll, UnixListener), io::Error> {
-    // FIXME: permissions! (umask before binding ?)
-    let mut listener = UnixListener::bind(&socket_path)?;
-    let poll = Poll::new()?;
-    poll.registry()
-        .register(&mut listener, JSONRPC_SERVER, Interest::READABLE)?;
-
-    Ok((poll, listener))
-}
-
 // Remove trailing newlines from utf-8 byte stream
 fn trimmed(mut vec: Vec<u8>, bytes_read: usize) -> Vec<u8> {
     vec.truncate(bytes_read);
@@ -109,11 +100,18 @@ fn handle_byte_stream(
     Ok(())
 }
 
-/// The main event loop for the JSONRPC interface
-pub fn jsonrpcapi_loop(mut poller: Poll, listener: UnixListener) -> Result<(), io::Error> {
+// For all but Windows, we use Mio.
+#[cfg(not(windows))]
+fn mio_loop(
+    mut listener: UnixListener,
+    jsonrpc_io: jsonrpc_core::IoHandler,
+) -> Result<(), io::Error> {
+    let mut poller = Poll::new()?;
     let mut events = Events::with_capacity(16);
-    let mut jsonrpc_io = jsonrpc_core::IoHandler::new();
-    jsonrpc_io.extend_with(RpcImpl.to_delegate());
+
+    poller
+        .registry()
+        .register(&mut listener, JSONRPC_SERVER, Interest::READABLE)?;
 
     loop {
         poller.poll(&mut events, Some(Duration::from_millis(10000)))?;
@@ -146,3 +144,29 @@ pub fn jsonrpcapi_loop(mut poller: Poll, listener: UnixListener) -> Result<(), i
         }
     }
 }
+
+// For windows, we don't: Mio UDS support for Windows is not yet implemented.
+#[cfg(windows)]
+fn windows_loop(
+    listener: UnixListener,
+    jsonrpc_io: jsonrpc_core::IoHandler,
+) -> Result<(), io::Error> {
+    for stream in listener.incoming() {
+        handle_byte_stream(&jsonrpc_io, stream?)?;
+    }
+
+    Ok(())
+}
+
+/// The main event loop for the JSONRPC interface, polling the UDS at `socket_path`
+pub fn jsonrpcapi_loop(socket_path: PathBuf) -> Result<(), io::Error> {
+    // FIXME: permissions! (umask before binding ?)
+    let listener = UnixListener::bind(&socket_path)?;
+    let mut jsonrpc_io = jsonrpc_core::IoHandler::new();
+    jsonrpc_io.extend_with(RpcImpl.to_delegate());
+
+    #[cfg(not(windows))]
+    return mio_loop(listener, jsonrpc_io);
+    #[cfg(windows)]
+    return windows_loop(listener, jsonrpc_io);
+}

src/main.rs

@@ -8,7 +8,7 @@ use crate::{
     bitcoind::actions::{bitcoind_main_loop, setup_bitcoind},
     config::parse_config,
     database::actions::setup_db,
-    jsonrpc::{jsonrpcapi_loop, jsonrpcapi_setup},
+    jsonrpc::jsonrpcapi_loop,
     revaultd::RevaultD,
 };
 
@@ -46,12 +46,9 @@ fn daemon_main(mut revaultd: RevaultD) {
         revaultd.bitcoind_config.network
     );
 
-    let (poller, listener) = jsonrpcapi_setup(revaultd.rpc_socket_file()).unwrap_or_else(|e| {
-        log::error!("Error setting up the JSONRPC server: {}", e.to_string());
-        process::exit(1)
-    });
+    let socket_path = revaultd.rpc_socket_file();
     let _jsonrpc_thread = thread::spawn(move || {
-        jsonrpcapi_loop(poller, listener).unwrap_or_else(|e| {
+        jsonrpcapi_loop(socket_path).unwrap_or_else(|e| {
             log::error!("Error in JSONRPC server event loop: {}", e.to_string());
             process::exit(1)
         })